The Singleton Pattern is one of the GoF (Gang of Four) Patterns. This particular pattern provides a method for limiting the number of instances of an object to just one. It's an easy pattern to grasp once you get past the strange syntax used. Consider the following class:
PHP 5 made significant improvements on the Object Orientated programming model of PHP 4 bringing it more in line with languages such as Visual Basic .NET and Java. The improved object model in PHP 5 makes developing applications using OOP much easier and gives you the programmer, greater flexibility. In this series of articles I will demonstrate the new features of the PHP 5 object and show you how to create a database abstraction layer similar to PEAR DB . I will also introduce you to a few design patterns that can be applied to common OOP related problems. In this article, I introduce you to some of the features of the PHP 5 object model. You will see how to create a database abstraction layer similar to the Pear DB abstraction layer.